Corrosivity of Crude Oils

ASTM International Committee G01 on Corrosion of Metals has an ongoing commitment to help the oil field industries adopt and use state-of-the-art techniques to control corrosion. As part of this commitment, Subcommittee G01.05 on Laboratory Corrosion Tests has approved ASTM G205, Guide for Determining Corrosivity of Crude Oils.

ASTM G205 is the result of collaboration among members of Task Group G01.05.11, part of Subcommittee G01.05 on Laboratory Corrosion Tests. The task group comprises oil pipeline company representatives, researchers, consultants and educators. The standard provides methodologies for the evaluation of crude oils under conditions normally occurring in oil and gas production, storage and transportation in pipelines.

Crude oil is normally not corrosive under pipeline transportation conditions. However, when water is present in the liquid state, oil pipelines are vulnerable to corrosion, which results, in part, from crude oil ingredients partitioning into the water.

ASTM G205 describes methods for determining the corrosivity of crude oils by a combination of three properties: (1) the emulation of the oil and water, (2) the wettability of the pipeline surface, and (3) the corrosivity of the water phase in the presence of crude oil. Based on the results, the standard classifies crude oils into corrosive, neutral, inhibitive and preventive hydrocarbons.

“In order to fully evaluate the corrosivity of crude oil under pipeline operating conditions, all three methods described in ASTM G205 should be used because each methodology evaluates different properties,” explains Sankara Papavinasam, Ph.D., CanmetMATERIALS, Natural Resources Canada, Hamilton, Ontario, Canada.

Before the publication of ASTM G205 extensive tests were carried out to refine the laboratory methodologies described in the standard using more than 15 crude oils from pipelines in North America. According to Papavinasam, obtaining crude oils from real operating oil production and transmission pipelines would not have been possible but for the leadership and support from several companies that participated in the consortium project. This project was partially funded through the Pipeline Research Council International, and the results were peer reviewed by PRCI members.

“We have been very supportive of this project and are glad to know that ASTM has incorporated the results of the research to develop and publish this key standard for the industry,” notes Cliff Johnson, president of PRCI.

“Although standards are available to evaluate the corrosivity of crude oil at higher temperatures, which occurs during refining, until ASTM G205 no standard methodology has been available to evaluate crude oil corrosivity under pipeline operating conditions,” observes Trevor Place, Enbridge Pipelines.

To purchase ASTM standards, visit www.astm.org and search by the standard designation, or contact ASTM Sales (phone: 877-909-ASTM; sales@astm.org).

CONTACT Technical Information: Sankara Papavinasam, PhD, CanmetMATERIALS • Hamilton, Ontario, Canada • Phone: 613-947-4603 | ASTM Staff: Jennifer Rodgers • Phone: 610-832-9694 | Upcoming Meeting: Nov. 13-15 • November Committee Week • Atlanta, Ga.

This article appears in the issue of Standardization News.